Japanese trading house Mitsui & Co said on Wednesday it would acquire a 40% stake in the Rio Tinto-operated Rhodes Ridge iron ore project in Western Australia for $5.34 billion, to strengthen its long-term earnings base.

Japanese trading house Mitsui & Co. will buy a stake in an Australian iron ore project for $5.3 billion, in a bet that the global steel industry will need high-quality raw materials to support its push to go green.

King & Wood Mallesons is acting for Japanese conglomerate Mitsui & Co on its $5.34 billion purchase of an interest in the Rhodes Ridge Iron Ore Project in Australia. The deal marks the largest ever single investment for Mitsui, the company's president and chief executive officer, Kenichi Hori, said in a speech announcing the acquisition.